Adjuvant systemic therapy of early stage breast cancer.

Adjuvant chemotherapy reduces the risk of recurrence and mortality in patients with early stage breast cancer. Anthracycline-based regimens are the most widely used standard in the United States. The inclusion of the taxanes into adjuvant chemotherapy programs offers an improvement in disease-free survival rates and probably overall survival rates compared to an anthracycline-based regimen alone. Although adjuvant chemotherapy is effective in all age groups, the magnitude of benefit is greatest in younger premenopausal patients. Treatment decisions need to be individualized. Dose-dense chemotherapy approaches are promising and can be considered an option for patients with early stage breast cancer. Adjuvant tamoxifen therapy should be administered for 5 years in patients with hormone receptor-positive breast cancer. Adjuvant tamoxifen should be administered after the completion of adjuvant chemotherapy. Data from the ATAC (Arimidex, tamoxifen, alone, or in combination) trial provide a compelling argument for choosing anastrozole as adjuvant endocrine therapy in postmenopausal women with hormone receptor-positive early stage breast cancer. Long-term follow-up of patients is necessary to determine the effects of chronic aromatase inhibitor treatment on bone density, cognitive function, and other endpoints.